1. Field of the Invention
This invention relates to devices and systems for permitting the operation of a vehicle by a physically-impaired person. More particularly, the present invention relates to systems for controlling, through a single unit the acceleration and braking functions of a conventional vehicle. Still more particularly, the present invention relates to a system having a single control component through which the accelerator and brake of the vehicle are operable by hand while permitting standard operation of the vehicle by an able-bodied person. The system of the present invention includes means for enhancing response sensitivity.
2. Description of the Prior Art
In the past there have been developed a number of systems designed to assist the physically disabled to operate as "normal" a life as possible. More recent systems have been designed to permit such an individual to be self-sufficient. One key type of system for enabling such self-sufficiency relates to the operation of motor vehicles. In particular, there have been created either vehicles specifically adapted for use by physically-impaired individuals, or devices for adapting a standard vehicle for use by physically-impaired individuals. Of course, the custom-made vehicles are limited to use by a physically-impaired person, generally cannot be operated by an able-bodied person without the extensive training required by the vehicle owner, and they are much more expensive than standard vehicles. The devices available and made for adapting a standard vehicle to special use vary widely and impose their own limitations.
As noted in an earlier patent of the present applicant, U.S. Pat. No. 5,086,870 entitled "Joystick-Operated Driving System" (hereinafter the Bolduc patent), there are several hundred thousand Americans who are paraplegic or quadriplegic (i.e., suffer from restricted motion and strength in one or more limbs of the body) and who cannot simply step into their automobiles and drive away. For these individuals the production-line automobile does not provide the mobility most take for granted. Devices adaptable to production vehicles for use by impaired individuals have been somewhat successful.
One such device is the control system of Ahnafield (U.S. Pat. No. 4,722,416). Ahnafield describes the use of hydraulic cylinders for operating the steering, acceleration and braking of a vehicle. Control of all of the hydraulic cylinders is achieved through the operation of a remote manipulator and the hydraulic pressure used in the cylinders is delivered by the vehicle's own hydraulic pump. The remote manipulator described by Ahnafield comprises a single joystick of the type well known in the field of motorized wheelchairs. Such manipulators provide two axes of motion wherein side-to-side motion is translated into left and right turns, and forward and backward motion are translated into acceleration and braking.
Another type of control device apparently adaptable to production-line vehicles is the one disclosed by Johnson et al. (U.S. Pat. No. 4,476,954). This device also operates by means of a single joystick, similar to the one described by Ahnafield. The joystick of the Johnson system controls input to DC motors which are then used to rotate the steering wheel and to depress the accelerator and brake pedals. In particular, the joystick has a range of motion that approximates the range of motion of an airplane joystick. Although the use of such a joystick for controlling a vehicle is of particular interest to the physically-impaired individual, such a range of motion may limit the usage of the Johnson device to those individuals with the dexterity to reach and maintain full extension as the driving situation dictates. More recent systems providing similar capabilities include the devices described by Chuang (U.S. Pat. No. 5,228,356) and Schoch et al. (U.S. Pat. No. 5,261,291).
As previously noted in the prior patent of the present applicant, the noted adaptable devices utilizing a joystick method of operating a vehicle all fail in one particular aspect: they do not fully address the needs of the physically-impaired individual. Although such individuals have physical deficiencies, they respond to driving stimuli utilizing the same mental processes as fully-functional individuals. In order to provide vehicle access to all but the most severely impaired, there must be a control system which translates the limited movement and strength of the individual into commands that direct the vehicle to operate as a function of the mental process rather than the physical process. To do so, the translation from electronic input, initiated by the physically-impaired individual, to operation of the vehicle must be as smooth as the translation from the brain to the hands and feet of the normal individual. It is also necessary in such a system to permit control of the vehicle in the event of catastrophic failure of the control system. It was further noted that such an adaptation system should provide for fast and simple conversion of the unitary mode of control to a conventional able-bodied mode of control.
The system described in the Bolduc patent achieved the noted goals. However, that system was directed to enabling even the most severely disabled individual to operate a standard vehicle. While that system is relatively simple in comparison to prior devices, and in comparison to a customized vehicle, it is nevertheless, more than is required for the individual with something more than an extremely limited range of physical capabilities. That is, the person who may have complete upper body control but little or no lower body control, or at least some sort of limitation preventing full use of one or both legs. That person can operate the steering wheel of a conventional vehicle but cannot operate the accelerator and brake. The single-unit operating system for such a person interferes with the ability to move the conventional steering wheel, and includes equipment and control subsystems that are otherwise unnecessary. As a result, the applicant created a single-element device to be used in controlling only the accelerator and the brake of a conventional vehicle.
Earlier devices created to provide manual means for operating the accelerator and brake of a vehicle have been described by Conlyn, Jr. et al. (U.S. Pat. No. 4,946,013), Ulrich (U.S. Pat. No. 4,788,879), and Howell (U.S. Pat. No. 4,993,509). The device disclosed by Conlyn is a relatively simple mechanical system having a handle joined to a brake actuator and an accelerator actuator. As applied, the Conlyn device interferes with standard operation of the vehicle by an able-bodied person. In addition, the device fails to provide feedback sensitivity to allow smooth control of the brake and accelerator. The Ulrich device has two separate but linked handles, one for regulation of the accelerator and the other for the brake. The Ulrich device fails to provide ready access to the brake and gas pedals and does not offer feedback means that would give the driver a "feel" for the vehicle's operation. The system disclosed by Howell also permits manual operation of the gas and brake. However, as with the other earlier devices, it is a simple combination of mechanical linkages offering no easy access by able-bodied drivers and no feel for vehicle operation. Moreover, the Howell device is connected to the steering wheel, further limiting accessibility.
It has been observed that prior-art systems apparently available for manual operation of the accelerator and brake pedals of a vehicle involve the use of essentially entirely mechanical or hydraulic linkages. That is, the input from the driver is coupled to a mechanical element that in turn controls mechanical components coupled to the accelerator and brake. However, such systems fail to take into account the constantly adapting evaluations of the driver as the vehicle is being operated. The prior mechanical and hydraulic linkages simply cannot respond quickly enough or adequately enough to the driver's actions carried out under normal thought processes while in a driving situation. Moreover, they fail to make the input device adjustable so that the "feel" of the input means can be set to a particular person's capabilities. Current devices all provide a single type of feedback in the input device, regardless of the driver's needs.
The present applicant has created a manually-operated gas/brake system that overcomes several deficiencies associated with the prior devices. That system leaves the vehicle pedals free for able-bodied use even with the system installed. The brake pedal is controlled through a direct mechanical brake applicator means that includes an arm with a roller that, as it rotates, applies pressure to the brake pedal and/or its linkage. This is achieved either by connection of a cable directly to the pedal. Alternatively, the brake applicator means may include, but is not limited to, the use of gears, pulleys, belts, levers, linear ball screws, and linear motors. The accelerator is applied through accelerator application means such as by reversing the rotation of the roller at the brake disc, wherein a cable pulls a lever which either pushes or pulls the accelerator linkage. Alternatively, accelerator application means may include, but is not limited to, the use of a direct cable attachment, levers, pulleys, belts, or a second separate motor operating in a linear or rotational manner.
In the preferred embodiment of the previously developed system, control is provided through a single-axis joystick tied to the brake and accelerator application means. Other input means include rotational, linear, force, and optical devices all tied to a controller that translates input into mechanical motion of the brake and accelerator pedals. As noted in the Bolduc patent, it is necessary to accommodate the physical impairment throughout the entire control system. In particular, it is necessary to provide a response to joystick operation which accounts for the acceleration and braking patterns which are most natural for the human brain. This is achieved through the use of a joystick with a small range of motion, a joystick-interfacing design which permits "digitized" acceleration and braking control, backup control systems and mechanical components that provide a smooth transition from a limited physical input to a desired vehicle movement.
While the system described in the Bolduc patent addressed many of the failings in the prior complete single-control-unit operating devices, as earlier noted, it nevertheless is directed to assisting those persons who are essentially entirely handicapped. That is, it provides for operation of the accelerator, brake and steering via the single joystick. The system also requires some skilled effort in order to make the vehicle conventionally operable-not as much effort as the earlier similar devices-but particular technical knowledge is needed. For these reasons, the system is fairly expensive, particularly for the individual who has the capability to operate the steering wheel and therefore does not need that portion of the prior Bolduc device that includes such operation. Another limitation of the prior Bolduc system is the inability to adjust the tension of the control unit so that operator sensitivity and a feel for the way the device moves the vehicle are realized. This is a deficiency in all manual control accelerator/brake control units available.
Therefore, what is needed is a control device for the operation of a vehicle's accelerator and brake pedals by a physically-impaired individual that provides a means by which the normal thought processes used in accelerating and braking can be implemented smoothly regardless of the operator's gross physical condition. What is also needed is a control device for the operation of a vehicle's accelerator and brake pedals that is simple to install and operate and that leaves the motor vehicle fully operable for any non-impaired driver. Still further, what is needed is a control device for the operation of a vehicle's accelerator and brake pedals that includes means for adjusting the response of the input device to fill the needs of a particular driver.